Siegfried.lenz
Celestial navigation would be cool and pretty much immune to jamming. I wonder what kind of accuracy it could achieve with today’s technology.
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Celestial navigation would be cool and pretty much immune to jamming. I wonder what kind of accuracy it could achieve with today’s technology.
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An inertial system that is occasionally synched with GPS or ground stations has been proposed by many, for decades.
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US Gov`t killed our Loran navigation GPS backup
Like many aircraft operators I removed the King Loran reciever from my plane to make room for the ADS-B installation. I am thinking the decision to shut down the Loran system was pretty lame. The auto pilot in my aircraft quit working in flight when the system was shut down .The autopilot was coupled to the Loran receiver. More than 200,000 US civilian and military aircraft and boats had Loran receivers… Consider that a single F-22 costs $350 million including developmental and other costs and for the price of of one aircraft, we could have operated the entire LORAN-C system for more than four years. But the Department of Homeland Security ordered the Coast Guard to shut down and demo the LORAN stations back in February 8, 2010 .
So what? Doesn’t the Global Positioning System (GPS) do the same thing and better? It guides unmanned aerial vehicles, tells troops and their supporting arms exactly where they are, synchronizes time and cell-phone antenna, navigates ships. Sure it does, until it fails, or an enemy disables it. Then what do we do? A good answer was to keep a backup LORAN system, and even upgrade it to the enhanced version, e LORAN, which was planned and other countries keep in operation…
Many think that disabling the satellite system that powers the GPS is unlikely because terrorists won’t be blowing a satellite out of the sky.This maybe true, but it’s relatively easy to cripple the GPS without shooting down a satellite because a space system has two other vital segments – the low power up-and-down links and the ground station. The links can be neutralized by electronic assault. North Korea has done this. The ground station is vulnerable to a variety of stoppages, including mundane factors like power outages and even simple human error. The solution of course is to have a backup system in order to prevent the chaos of a disabled GPS – a chaos that could cause a crash of our financial system – a problem that would make the annual $36 million cost of operating LORAN look like peanuts.
Another dollar comparison is in order. The estimated cost to upgrade LORAN-C to LORAN e , which could operate for at least 20 years,was $150 million. The projected cost of eight new GPS satellites is $1.8 billion, in addition to launch and operational costs.
If this minor cost of continuing the LORAN system seems to be a no-brainier, then what happened? Lawrence Husick explains a senior fellow in the Foreign Policy Research Institute’s Center on Terrorism and Counter-Terrorism, wrote that the LORAN system “lacked powerful contractors and lobbyist who could profit from Lorans operation and congressional sponsors.These remote radio installations that bring few jobs, and dollars had no support.” In short, he says, “Loran is an orphan.” There is no money to be made by defense contractors. The Coast Guard maintained the system as part of its job description. He adds that February 8, 2010 marked the day the Department of Homeland Security put the entire nation at risk despite the protest from pilots to the FAA.
Conclusion: “It is easy to see how a small system like Loran just got lost in the shuffle of bean-counters trying to cut corners.” The conclusion: We were penny wise and pound foolish. We could spend a few pennies to prevent a navigation melt down one day and it may be coming soon. George Gould pilot @ Galceston Scholes airport KGLS Galveston Texas
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Definitely need a backup, but as usual, simple answers won’t satisfactorily resolve the problem. As well as being inherently low rate, less accurate and requiring a fairly extensive worldwide network of easily targeted ground stations, LORAN has the same weakness to jamming as GPS, plus that jamming & spoofing can be done from a distance. Celestial and inertial both have their own weaknesses, so the real answer will be a complementary meld of multiple techniques.
The Chinese and Russians are in the same boat, they rely entirely on it too.
Celestial Nav… imagine that… Back in the days of the ASN-24 and ASN-35 computers on the C-141A, we sure got around the world just fine. The Nav did 3-star fixes and the -24 had a Star Tracker that we never really used. Then, the Delco Carousel 4 had Tacan and DME-DME updating and found those same places very accurately AND we didn’t have the Navigator stealing box lunches! (just kidding about the Nav). In the 747 Classic, the Delco then the Litton 92 were extremely accurate. Could update both from the VOR / DME. On the “tracks”, without updates, the -92 would be within a wingspread width of the aircraft that had GPS before we did.
Loran, GPS, etc, all can be spoofed, flummoxed, or simply jammed. If it is electronic, it can be messed with, period. Thus, for this discussion, only inertial-type systems are relatively safe. They still have to be EMP hardened though.
Long ago, and kind of far away, another pilot, myself, a Navigator, and a Crew Chief, took 3 C-131s (CV-340) across the Pacific (2 west, 1 east) with naught more than DR, Consolan, and a Sextant. Modern systems are wonderfully accurate and useful but the Mark I eyeball and planning will still work.
That’s all well and good for the military, but what about the civilian world? It’s more likely that an adversary would try to disrupt civilian air traffic by jamming GPS.
Any radio-based navigation system can be jammed, but if multiple navigations systems are spread over multiple frequency bands, it makes it more difficult to completely shut down air navigation. And I’m not convinced that the VOR MON will leave enough of a backup. Sure, VORs and LORAN aren’t perfect either, but VOR+LORAN would have left a fairly robust backup system to GPS. It also seems like it wouldn’t be too difficult to integrate LORAN and GPS into the same receiver so they can both cross-check each other.
Inertial and celestial navigation are of course naturally resistant to jamming, but they also require every aircraft to be equipped with them. I hope this doesn’t turn into another mandate for GA aircraft.
That’s fine for VFR down low, but not particularly helpful when you’re in IMC or the flight levels.
You are so very correct regarding the waste of not updating LORAN. TLS is another system that was smothered by the pie in the sky promise of GPS. https://www.anpc.com/instrument-landing-systems/ While I am pleased with modern GPS performance, it sure took forever to deliver.
Other shortcomings:
Fixed location sources: Civil engineers design and build targets for aerospace engineers.
There’s a reasonably cheap and easy answer for most of us (i.e. the US civil aviation sector). I read a paper a few months back on the possibility of using the ADS-B ground stations as a backup RNAV source. If I recall correctly, the ground station signals included the necessary data to do an accurate time-of-flight calculation. You need have to have an accurate timing source onboard (not an atomic clock of your own, just a good digital clock), at least three towers in view, and a modest microcontroller to crunch the numbers.
The team that did the study were able to triangulate a position +/- 20 meters. I’m a bit surprised it hasn’t simply become a standard feature on ADS-B receivers. Here’s a link to the paper: https://navi.ion.org/content/68/2/293
Neat. Does anyone have any time in an Angel Twin? They’re STOL equipped, heavy lifters and built like tanks, according to their web page.
Uhmmm, what exactly is the “new solution for the aviation market after decades?” I believe the Twin Otter (used), Caravan, Kodiak, Dornier 228, Beaver, Helio Courier, and several others have been “making the world`s extreme commercial airports accessible with comfort, safety and style” for some time now (well, the Beaver is debatable on comfort…). While the proposed performance is impressive, for the same price or less, I’ll opt for something that takes Jet A and has greater remote support, thank you.
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It would be interesting to put it in context with the aircraft that are already servicing these same airports. How does the performance compare with the Twin Otter, or Islanders, for example? Some of these airports are also served by Caravans–and though it is a single engine, it IS a turboprop.
Interesting that they swapped Lycoming 540s for Continental 520s–do you suppose that has something to do with the need for turbocharging in some parts of the world?
It’s pretty hard to compete with something like the Twatter–turbine reliability, heavy duty fixed gear–large cabin volume, super STOL, great climb gradient. It DEFINES the STOL commuter class. An attempted “replacement” will likely end up being like the “replacement” for the DC-3-companies tried to produce that replacement for over 50 years–the best “replacement” was to simply convert the DC-3 to turbines, and let them soldier on!
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They mean it’s a replacement for the Islander. Since they’ve made like 1,300+ of those things, and most are decades old, it’s a great market to target. Avgas (G100UL?) piston puddle jumpers occupy a specific market niche for low operating costs, particularly at lower altitude. Jet A turboprops are great for certain applications, but you will have higher fuel burn and the hardware is more expensive to buy and maintain. Operators of twin piston Cessna, Piper and Islanders could have made the switch to turboprops long ago, instead they just want a new twin piston to replace them.
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The specs are meant to be an Islander replacement - passenger load, take off and landing distance, etc. Twin Otters carry twice the passenger load, so not a 1-to-1 replacement. Cape Air also operators a few Islanders, I’m sure they told Tecnam EXACTLY what they wanted in a replacement.
DC-3s are (still) great (go Basler!), but all the new utility aircraft have things that can’t be retrofitted to that airframe. The Skycourier has so many features that will make it perfect for its application: square cross section, container-sized cargo door, high wing, fixed gear, etc. New utility planes like the Skycourier or P2012 STOL may not make many trips to Antarctica, but you only need a few Basler 67s to fill that need.
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Valid points, BUT:
Given that most of these “shuttle” aircraft are not that far from the airport that “feeds” the STOL-port–does speed make much difference? For the most part, the marketplace has said “No.” An extra few knots over less than 100 n.m. is negligible.
Given that most of the airports on the video are vacation destinations–that usually means LOTS of baggage–and bulky things like skis or SCUBA tanks–compromising the payload.
Since most of the destinations aren’t connected by road, that means that everything to serve the hotel industry has to come in by air or boat–lots of air freight. “There is too much room and weight allowance for the vacation destination”–said NOBODY–EVER.
You have to ask yourself–“Would you rather fly with turbine engines, or temperamental GEARED piston engines?” Frankly, I’d rather fly in a Caravan with one reliable PT-6 (we’ve flown a Caravan to 83 countries around the world, plus Antarctica)–or better yet, TWO PT-6s on a Twin Otter.
I don’t see this as “right-sized” for the market.
Especially these days, fuel costs will be a consideration for business/charter outfits, who won’t let the grass grow under their birds. I rode aboard a puddle jumper (Islander) between Concord, CA and KSFO, and it was an adventure.
The geared engines can turn at higher RPM and thus make more power. Continental still makes the geared GTSIO model, Lycoming only has direct drive.
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One of the good things about Geared 520 is that it’s single engine service ceiling performance is better than a PT-6-20, or -21. Take a C-90 King Air takeoff and engine failure off KTVL and it’s almost a guaranteed off airport landing.
I’m no fan of Tecnam. The build quality on there older birds was dirt. I haven’t seen any of the new ones too close up, so cannot say if they’ve gotten better or not.
That being said, the comments here are borderline silly, and they remind me of comments on lots of car sites from people who really cannot understand why anyone needs “X”. The fact that car companies sell hundreds of thousands of cars with “X” is simply proof to these people that the public is stupid. “X” includes things like AWD, raised suspensions, and traction control.
Instead, we are treated to insistence that no new models are needed because the old planes are just better.
Which is why there are hardly any new planes or new aviation enthusiasts, and a new antique plane costs stupid money.
Problem with geared engines from either manufacturer is that the gearboxes are fragile, not tolerant of throttle “jockeys”. It will be interesting to see how well the Continentals hold up in repeated short legs this plane is designed for.
Eric W.,
U duh Mannn ! I agree completely with absolutely everything you wrote (above).
Tecnam products have always reminded me of Lancia autos: sexy supermodels upon first looks then ongoing maintenance headaches. Oh, well
Quote attributed to Santayana and Winston Churchill is appropriate here—“Those that fail to learn from history are doomed to repeat it.”
There is a REASON why geared/opposed engines are no longer offered—THEY DO NOT WORK! If they DID work—we wouldn’t have turbines—the specific fuel consumption is better for piston engines—but they are not reliable.
You don’t see piston engine airliners—airlines (and passenger) gladly pay more for reliable engines.
For business aircraft—the geared supercharged engines on Queen Airs were so unreliable that they were reolaced with turbines—begetting the KING AIR—perhaps the most reliable prop-driven GA airplane—the lowest cost to insure—and the biggest seller. (the Queen Air did enjoy a successful afterlife—when Ed Swearingen hung 400 hp direct drive Lycoming in it—getting rid of the problematic 340 and 385 hp geared Lycomings)
Piper learned the lesson on the p Navajo—Eliminating the geared Lycomings, and begetting the Cheyenne.
Commander famously had a number of models stillborn—remember the 720 Alticruiser? They became the 680 and 690.
There is a REASON why Cessna no longer makes 421s—the engines just didn’t hold up. The Conquest 1 (Cessna 425) with PT 6s replaced it—as well as the Conquest II with Garrett’s.
Single engines—Helio tried geared engines—and replaced them with direct-drive engines.
Piper was going to revolutionize business air travel with the infamous Malibu despite a valiant effort to make them work—none of Pipers big pressurized piston engine singles stood up to operation at high weights—or problems of operating a marginally-powere single in the flight levels (IF you could REACH the flight levels!)
Cessna—the leading producer of “working” utility singles in the world—didn’t even attempt a piston engine on their Caravan utility airplane—they went straight to a turbine—and cornered the market.
There is a REASON that big horizontally opposed piston engines don’t work (let’s not stop it at horizontally opposed engines—even large RADIAL engines have a reliability problem )the reason that the military, the airlines, and the corporate world abandoned them!)
Yet this “new” model—with a cost of over a million dollars—floats a proposal for a STOL aircraft (even HARDER on engines!) powered with an unreliable engine???
There is a REASON why “working airplanes” (like commuters, and Ag planes)—are powered with turbines—despite their poorer fuel specifics—it’s because they WORK—and they are DEPENDABLE. Tecnam will apparently have to learn the lesson for themselves. Perhaps somebody should provide them with Churchill’s quote.
The Lycoming engines make the same power as the geared Continentals acc to the Tecnam site. I see the gearbox as a potential liability, and its lower TBO of 1600hrs will affect an operator’s bottom line.
To me, a curious choice as they have the same power rating as the original Lyc TEO-540 but with a gearbox to lower TBO.
Every time I see turbines bolted on the Gooney Bird, I think “Is nothing sacred?” I just love that old bus, but they’re supposed to rumble, not screech.
It reduces the prop tip speed allowing a bigger prop. The effect of a larger prop is better thrust particularity at low speed.
I remember when our USAF Aircraft Delivery Unit on Guam briefed the receivers (Usually Fighter Gaggles) for flights across the Pacific, and the tanker (KC-135) contingent would sorta hint that they would ‘affirm’ their navigation calculations with the IMUs installed on the fighters. They also had a Duck Butt C-130 orbiting at Bingo coordinates to aid their journeys, particularly when single-engine receivers were flown.